Justin played for London Irish between 1994 and 2007, making at total of 279 appearances and scoring 58 tries, including 2 of the Exiles tries in the 2002 Powergen Cup Final victory over Northampton Saints.
Justin played for both England & Ireland at age group levels and at full international level, he won 25 caps for Ireland, scoring 8 tries.
After leaving London Irish, Justin spent a couple of seasons as Player/Coach at Doncaster Knights.
He returned to London Irish in 2010 to work with the academy and was appointed defence coach for the 2011-12 season.
After this, Justin’s rugby life took him to East Grinstead, his first rugby club, which he had originally joined at the age of 6.